Chemical processes especially when carried out in the liquid or gaseous phase involve handling of large volumes of material in closed systems. The material in such systems is contained in tanks and large vessels which are connected to each other by piping in order to transfer liquid from one vessel to another. Chemical processes as well as other processes involving the handling of liquids require precise temperature control for maximum efficiency. It is often difficult, inefficient, cumbersome or impractical to measure temperatures by immersion of a thermometer or other temperature measuring probe directly in the liquid being processed. One method of measuring the temperature of liquids in chemical processes is to measure the surface temperature of the vessel or pipe containing the liquid whose temperature it is desired to measure.
For this purpose there are provided relatively flat shaped temperature sensors which can be clamped or strapped to the surface of the pipe or vessel, the temperature of which it is desired to measure. In order to achieve precise temperature control, such devices must be calibrated against a known standard at the point of use, i.e., in the process area where the temperature is being measured.
A need, therefore, exists for a portable temperature calibration device whereby the accuracy of the temperature sensor can be compared to the accurate known standard and appropriate adjustments made to the process controller which is governed by the temperature sensor being calibrated.